Worm Breeder's Gazette 12(2): 43 (January 1, 1992)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We planned mosaic analysis of the functional expression of a cloned gene using an extrachromosomal array carrying lacZ as a marker. In this method, a mutant is first rescued by an extrachromosomal concatemer consisting of an introduced wild type gene and "universal promoter"-lacZ chimeric gene. Mosaic nature of the extrachromosomal array and X-gal staining that visualize cells with the array may allow mosaic analysis of the functional expression of the cloned gene. Since a gene for a peptide elongation factor 1alpha (EF1alpha) was expected to carry a universal promoter, we tried to clone this gene from C. elegans by PCR and library screening. Two genes (EF1alpha-1 and EF1alpha-2) and their cDNAs were cloned. EF1alpha-1 (clone EF-G1) was mapped by A. Coulson on LG III, and EF1alpha-2 (clone EF-G5) was mapped by Coulson & Shownkeen on LG X. Although some ambiguous bases remain, these two EF1 alphagenes seem to encode proteins with the same amino acid sequence. Since the amino acids sequence predicted from the EF1alpha-1 cDNA and genomic DNA shows 83% homology with human EF1 alpha(see figure), EF1alpha-1 and EF1alpha-2 are thought to be C. elegans EF1 alphagenes. Expression of an EF1alpha-1/lacZ chimeric gene (2.7 kb fragment including a short N terminal coding region and an upstream sequence inserted to SalI site of pPD22 .04)has been observed in many cells including hypodermis, neuron, uterus, pharynx, but probably not in intestine and body wall muscles. Therefore, EF1alpha-1 promoter might not necessarily be universal. Other chimeric gene constructs may be expressed universally,or expression from EF1alpha-2 may complement EF1alpha-1 expression.
[See Figure 1]